Autism
Neurodevelopmental disorder From Wikipedia, the free encyclopedia
Autism spectrum disorder[a] (ASD), or simply autism, is a neurodevelopmental disorder characterized by repetitive, restricted, and inflexible patterns of behavior, interests, and activities, as well as difficulties in social interaction and social communication.[7] Sensory processing differences can impair functioning in different areas, such as developing social relationships or performing instrumental activities of daily living. Common associated traits such as motor coordination difficulties are not required for diagnosis. A formal diagnosis requires that symptoms cause significant impairment in multiple functional domains; in addition, the symptoms must be atypical or excessive for the person's age and sociocultural context.[8][9][10][11][12][13][14][15] Autistic traits fall on a spectrum, manifesting in different ways, with severity and support needs varying widely.[8][9][16] For example, some on the spectrum are non-speaking, while others have proficient spoken language.[17][18]
 | This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages)
|
The view that autism is solely or inherently a disorder has been challenged by the neurodiversity paradigm, which frames autistic traits as a natural variation of the human condition. This view is supported by the autism rights movement and is a topic of research.[19][20][21] The neurodiversity framework has sparked significant debate among autistic people, advocacy groups, healthcare providers, and charities, with disagreements about the nature, classification, and implications of autism as a diagnosis.[22]
The precise causes of autism are unknown in most individual cases. Research shows that the condition is highly heritable and polygenic, and environmental causes are relevant but contribute relatively little overall, with most environmental causes occurring in utero.[23][24][25] Boys are also diagnosed with autism at a significantly higher rate than girls.[26] Autism frequently co-occurs with attention deficit hyperactivity disorder (ADHD), epilepsy, and intellectual disability.[27][28][29]
The combination of broader criteria, increased awareness, and the potential increase of actual prevalence has led to considerably increased estimates of autism prevalence since the 1990s.[30][31] The World Health Organization estimates about 1 in 100 children were diagnosed with autism between 2012 and 2021, with a trend of increasing diagnoses over time.[b][5][6] This increasing prevalence has contributed to the myth perpetuated by anti-vaccine activists that autism is caused by vaccines.[32]
There is no known cure for autism. Some advocates dispute the need to find one.[33] Interventions such as applied behavior analysis (ABA), speech therapy, and occupational therapy can help autistic people gain self-care, social, and language skills.[34][35] Guidelines from the US Centers for Disease Control and Prevention (CDC) and European Society for Child & Adolescent Psychiatry endorse the use of ABA on the grounds that it reduces symptoms impairing daily functioning and quality of life,[34][14] but the National Institute for Health and Care Excellence cites a lack of high-quality evidence to support its use.[36] Additionally, some in the autism rights movement oppose its application due to a perception that it emphasizes normalization.[37][38][39] No medication has been shown to reduce autism's core symptoms,[14] but some can alleviate co-occurring problems.[40][41]
Classification
Summarize
Perspective
Spectrum model
Before the DSM-5 (2013) and ICD-11 CDDR (2024)[42] diagnostic manuals were adopted, autism was found under the diagnostic category pervasive developmental disorder. The previous system relied on a set of closely related and overlapping diagnoses such as Asperger syndrome and the syndrome formerly known as Kanner syndrome. This created unclear boundaries between the terms, so for the DSM-5 and CDDR, a spectrum approach was taken. The new system is also more restrictive, meaning fewer people qualify for diagnosis.[43]
The DSM-5 and CDDR use different categorization tools to define this spectrum. DSM-5 uses a "level" system, which ranks how in need of support the patient is. In this system, level 1 is the mildest form and level 3 the most severe.[44] In contrast, the CDDR system has two separate axes, intellectual impairment and language impairment,[45] as these are seen as the most crucial factors.
Autism is currently defined as a highly variable neurodevelopmental disorder[46] that is generally thought to cover a broad and deep spectrum, manifesting very differently from one person to another. Some have high support needs, may be nonspeaking, and experience developmental delays; this is more likely with other co-existing diagnoses. Others have relatively low support needs; they may have more typical speech-language and intellectual skills but atypical social/conversation skills, narrowly focused interests, and wordy, pedantic communication.[47] They may still require significant support in some areas of their lives. The spectrum model should not be understood as a continuum running from mild to severe, but instead means that autism can present very differently in each person,[48] with support needs depending on context and changing over time.[49]
While the DSM and ICD greatly influence each other, there are also differences. For example, Rett syndrome was included in autism spectrum disorder (ASD) in the DSM-5, but in the ICD-11 it was excluded and placed in the chapter on Developmental Anomalies. The ICD and the DSM change over time, and there has been collaborative work toward a convergence of the two since 1980 (when DSM-III was published and ICD-9 was current), including more rigorous biological assessment—in place of historical experience—and a simplification of the classification system.[50][51][52][53]
As of 2023, empirical and theoretical research highlights how established ASD criteria may be ineffective descriptors of autism as a whole, encouraging alternative research approaches, such as going back to autism prototypes, exploring new causal models of autism, or developing transdiagnostic endophenotypes.[54] There are proposed alternatives to the current disorder-focused spectrum model that deconstruct autism into separate phenomena: (1) a non-pathological spectrum of behavioral traits in the population,[55][56] (2) the effect of rare genetic mutations and environmental factors potentially leading to neurodevelopmental and psychological conditions,[55][56] and (3) individual cognitive ability's role in compensating for neurodivergence.[55]
ICD
The World Health Organization's International Classification of Diseases (11th revision), ICD-11, was released in June 2018 and came into full effect as of January 2022.[57][50] It describes ASD as follows:[58]
Autism spectrum disorder is characterised by persistent deficits in the ability to initiate and to sustain reciprocal social interaction and social communication, and by a range of restricted, repetitive, and inflexible patterns of behaviour, interests or activities that are clearly atypical or excessive for the individual's age and sociocultural context. The onset of the disorder occurs during the developmental period, typically in early childhood, but symptoms may not become fully manifest until later, when social demands exceed limited capacities. Deficits are sufficiently severe to cause impairment in personal, family, social, educational, occupational or other important areas of functioning and are usually a pervasive feature of the individual's functioning observable in all settings, although they may vary according to social, educational, or other context. Individuals along the spectrum exhibit a full range of intellectual functioning and language abilities.
— ICD-11, chapter 6, section A02
ICD-11 was produced by professionals from 55 countries out of the 90 involved and is the most widely used reference worldwide.
DSM
The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), released in 2022, is the current version of the DSM. It is the predominant mental health diagnostic system used in the United States and Canada, and is often used in Anglophone countries.
Its fifth edition, DSM-5, released in May 2013, was the first to define ASD as a single diagnosis,[59] which is still the case in the DSM-5-TR.[1] ASD encompasses previous diagnoses, including the four traditional diagnoses of autism—classic autism, Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS)—and the range of diagnoses that included the word "autism".[60] Rather than distinguishing among these diagnoses, the DSM-5 and DSM-5-TR adopt a dimensional approach with one diagnostic category for disorders that fall under the autism spectrum umbrella. Within that category, the DSM-5 and the DSM include a framework that differentiates each person by dimensions of symptom severity, as well as by associated features (i.e., the presence of other conditions or factors that likely contribute to the symptoms, other neurodevelopmental or mental conditions, intellectual disability, or language impairment).[1] The symptom domains are (a) social communication and (b) restricted, repetitive behaviors, and there is the option of specifying a separate severity—the negative effect of the symptoms on the person—for each domain, rather than just overall severity.[61] Before the DSM-5, the DSM separated social deficits and communication deficits into two domains.[62] Further, the DSM-5 changed to an onset age in the early developmental period, with a note that symptoms may manifest later when social demands exceed capabilities, rather than the previous, more restricted three years of age.[63] These changes remain in the DSM-5-TR.[1]
Assessment
Summarize
Perspective
![[icon]](#/media/File:Wiki_letter_w_cropped.svg){kind=small} |
A person for whom there is reasonable expectation of autism can undergo assessment to determine whether a formal diagnosis of autism is appropriate to describe the difficulties they are experiencing. Assessment should take into account both the person's reported and directly observed behavior.[64] There are no known biomarkers for autism that allow for a conclusive diagnosis.[65] In most cases, diagnostic criteria are applied from the World Health Organization's ICD-10 or ICD-11, or the American Psychiatric Association's DSM-5. One commonly used assessment tool is the Autism Diagnostic Observation Schedule, which can be used at any age. In children, assessment tools such as these are used in combination with other information, such as parent and teacher reports.[66]
According to the DSM-5-TR (2022), to receive a diagnosis of autism spectrum disorder, one must present with "persistent deficits in social communication and social interaction" and "restricted, repetitive patterns of behavior, interests, or activities".[67] These behaviors must begin in early childhood and affect one's ability to perform everyday tasks. Furthermore, the symptoms must not be fully explainable by intellectual disability or global developmental delay.
Signs and characteristics
Summarize
Perspective
Pre-diagnosis
 | This section may require cleanup to meet Wikipedia's quality standards. The specific problem is: Bulleted list not appropriate. (April 2025) |
For many autistic people, characteristics first appear during infancy or childhood and follow a steady course without remission (different developmental timelines are described in more detail below).[68] Autistic people may be significantly disabled in some respects but average, or even superior, in others.[69][70][71]
Clinicians consider assessment for ASD when a patient shows regular difficulty in social interaction or communication, restricted or repetitive behaviors (often called "stimming"), and resistance to changes or restricted interests.
These features are typically assessed with the following, when appropriate:
- Difficulties in obtaining or sustaining employment or education
- Difficulties in initiating or sustaining social relationships
- Connections with mental health or learning disability services
- A history of neurodevelopmental conditions (including learning disabilities and ADHD) or mental health conditions[72][73]
There are many signs associated with autism; the presentation varies widely. Common signs and characteristics include:[74][75]
- Less eye contact
- Little or no babbling as an infant
- Not showing interest in indicated objects
- Delayed language skills (e.g., having a smaller vocabulary than peers or difficulty expressing themselves in words)
- Less interest in other children or caretakers, possibly with more interest in objects
- Difficulty playing reciprocal games (e.g., peek-a-boo)
- Hyper- or hypo-sensitivity to or unusual response to the smell, texture, sound, taste, or appearance of things
- Resistance to changes in routine
- Repetitive, limited, or otherwise unusual usage of toys (e.g., lining up toys)
- Repetition of words or phrases, including echolalia
- Repetitive motions or movements, including stimming
Social and communication skills
According to the medical model, autistic people experience social communications impairments. Until 2013, difficulties in social function and communication were considered two separate domains.[76] The current social communication domain criteria for autism diagnosis require people to have difficulties across three social skills: social-emotional reciprocity, nonverbal communication, and developing and sustaining relationships.[1]
Social-emotional reciprocity
A deficit-based view predicts that autistic–autistic interaction would be less effective than autistic–non-autistic interactions or even non-functional.[77][non-primary source needed] But recent research has found that autistic–autistic interactions are as effective in information transfer as interactions between non-autistics are, and that communication breaks down only between autistics and non-autistics.[77][non-primary source needed][78][non-primary source needed] Also contrary to social cognitive deficit interpretations, research in 2019 recorded similar social cognitive performances in autistic and non-autistic adults, with both of them rating autistic individuals less favorably than non-autistic individuals, but autistic individuals showed more interest in engaging with autistic people than non-autistic people did, and learning of a person's autism diagnosis did not influence their interest level.[79][non-primary source needed]
Thus there has been a recent shift to acknowledge that autistic people may simply respond and behave differently than non-autistic people.[75] So far, research has identified two unconventional features by which autistic people create shared understanding (intersubjectivity): "a generous assumption of common ground that, when understood, led to rapid rapport, and, when not understood, resulted in potentially disruptive utterances; and a low demand for coordination that ameliorated many challenges associated with disruptive turns."[78] Autistic interests, and thus conversational topics, seem to be largely driven by an intense interest in specific topics (monotropism).[80][81]
Historically, autistic children were said to be delayed in developing a theory of mind, and the empathizing–systemizing theory has argued that while autistic people have compassion (affective empathy) for others with similar presentation of autistic features, they have limited, though not necessarily absent, cognitive empathy.[82] This may present as social naïvety,[83] lower than average intuitive perception of the utility or meaning of body language, social reciprocity,[84] or social expectations, including the habitus, social cues, and some aspects of sarcasm,[85] which to some degree may also be due to co-occurring alexithymia.[86] But recent research has increasingly questioned these findings, as the "double empathy problem" theory (2012) argues that there is a lack of mutual understanding and empathy between both non-autistic persons and autistic individuals.[87][88][89][90][91]
Verbal, minimally verbal, or nonverbal communication
Differences in verbal communication begin to be noticeable in childhood, as many autistic children develop language skills at an uneven pace. Verbal communication may be delayed or never developed (non-speaking autism), while reading ability may be present before school age (hyperlexia).[92][93] Less joint attention seems to distinguish autistic from non-autistic infants.[94] Infants may show delayed onset of babbling, unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the caregiver. In their second and third years, autistic children may have less frequent and less diverse babbling, consonants, words, and word combinations, and their gestures may be less often integrated with words. Autistic children are less likely to make requests or share experiences and more likely to simply repeat others' words (echolalia).[95] The CDC estimated in 2015 that around 40% of autistic children do not speak at all.[96] Autistic adults' verbal communication skills largely depend on when and how well speech is acquired during childhood.[92]
Autistic people display atypical nonverbal behaviors or show differences in nonverbal communication. They may make infrequent eye contact, even when called by name, or avoid it altogether. This may be due to the high amount of sensory input received when making eye contact.[97] Autistic people often recognize fewer emotions and their meaning from others' facial expressions, and may not respond with facial expressions expected by their non-autistic peers.[98][93] Temple Grandin, an autistic woman involved in autism activism, described her inability to understand neurotypicals' social communication as leaving her feeling "like an anthropologist on Mars".[99] Autistic people struggle to understand the social context and subtext of neurotypical conversational or printed situations, and form different conclusions about the content.[100] Autistic people may not control the volume of their voice in different social settings.[101] At least half of autistic children have atypical prosody.[101]
Developing and sustaining relationships
What may look like self-involvement or indifference to non-autistic people stems from autistic differences in recognizing other people's personalities, perspectives, and interests.[100][102] Most published research focuses on the interpersonal relationship difficulties between autistic people and their non-autistic counterparts and how to solve them through teaching neurotypical social skills, but newer research has also evaluated what autistic people want from friendships, such as a sense of belonging and benefits to mental health.[103][104] Children on the autism spectrum are more frequently involved in bullying situations than their non-autistic peers, and predominantly experience bullying as victims rather than perpetrators or victim-perpetrators, especially after controlling for co-occurring psychopathology.[105] Prioritizing dependability and intimacy in friendships during adolescence, coupled with lower friendship quantity and quality, often leads to increased loneliness in autistic people.[106] As they progress through life, autistic people observe and form models of social patterns, and develop coping mechanisms, some of which are referred to as "masking".[107][108]
Restricted and repetitive behaviors
Autism includes a wide variety of characteristics. Some of these include behavioral characteristics, which widely range from slow development of social and learning skills to difficulties creating connections with other people. Autistic people may experience these challenges with forming connections due to anxiety or depression, which they are more likely to experience, and may respond by isolating themselves.[109][110]
Other behavioral characteristics include uncommon responses to sensations (such as sights, sounds, touch, taste and smell) and difficulties keeping a consistent speech rhythm. The latter influences social skills, leading to potential difficulties in understanding for interlocutors. Autistic people show behavioral characteristics that typically influence development, language, and social competence. Their behavioral characteristics can be observed as perceptual disturbances, disturbances of development rate, relating, speech and language, and motility.[111]
The second core feature of autism is a pattern of restricted and repetitive behaviors, activities, and interests. To be diagnosed with autism under the DSM-5-TR, a person must have at least two of the following behaviors:[1][112]
- Repetitive behaviors – Repetitive behaviors such as rocking, hand flapping, finger flicking, head banging, or repeating phrases or sounds.[113] These behaviors may occur constantly or only when the person gets stressed, anxious, or upset. These behaviors are also known as stimming.
- Resistance to change – A strict adherence to routines such as eating certain foods in a specific order or taking the same path to school every day.[113] The person may become distressed if there is a change or disruption to their routine.
- Restricted interests – An excessive interest in a particular activity, topic, or hobby, and devoting all their attention to it. For example, young children might completely focus on things that spin and ignore everything else. Older children might try to learn everything about a single topic, such as the weather or sports, and perseverate or talk about it constantly.[113]
- Sensory reactivity – An unusual reaction to certain sensory inputs, such as negative reaction to specific sounds or textures, fascination with lights or movements, or apparent indifference to pain or heat.[114]
Autistic people can display many forms of repetitive or restricted behavior, which the Repetitive Behavior Scale-Revised (RBS-R) categorizes as follows.[115]
- Stereotyped behaviors: Repetitive movements, such as hand flapping, head rolling, or body rocking.
- Compulsive behaviors: Time-consuming behaviors intended to reduce anxiety, that a person feels compelled to perform repeatedly or according to rigid rules, such as placing objects in a specific order, checking things, or handwashing.
- Sameness: Resistance to change; for example, insisting that the furniture not be moved or refusing to be interrupted.
- Ritualistic behavior: Unvarying pattern of daily activities, such as an unchanging menu or a dressing ritual. This is closely associated with sameness and an independent validation has suggested combining the two factors.[115]
- Self-injurious behaviors: Behaviors such as eye-poking, skin-picking, hand-biting and head-banging.[94]
Mental health, self-injury and suicide
Self-injurious behaviors are relatively common in autistic people, and can include head-banging, self-cutting, self-biting, and hair-pulling.[116] Some of these can result in serious injury or death.[116] Autistic people are about three times as likely as their non-autistic counterparts to engage in self-injury.[117]
Theories about the cause of self-injurious behavior in children with developmental delay, including autistic children, include:[118]
- Frequency or continuation of self-injurious behavior can be influenced by environmental factors (e.g., reward in return for halting self-injurious behavior). This theory does not apply to younger autistic children. There is some evidence that frequency of self-injurious behavior can be reduced by removing or modifying environmental factors that reinforce the behavior.[118]: 10–12
- Higher rates of self-injury are noted in socially isolated autistic people. Studies have shown that socialization skills are related factors to self-injurious behavior for autistic people.[119]
- Self-injury could be a response to modulate pain perception when chronic pain or other health problems that cause pain are present.[118]: 12–13
- Anomalies in basal ganglia connectivity may predispose to self-injurious behavior.[118]: 13
Risk factors for self-harm and suicidality include circumstances that could affect anyone, such as mental health problems (e.g., anxiety disorder) and social problems (e.g., unemployment and social isolation), plus factors that affect only autistic people, such as actively trying to behave like a neurotypical person, which is called masking.[120] Approximately 8 in 10 autistic people have a mental health problem in their lifetime, in comparison to 1 in 4 of the general population.[121][122][123] A 2019 meta-analysis found autistic people to be four times more likely to have depression than non-autistic people, with approximately 40% of autistic adults having depression.[124]
Rates of suicidality vary significantly depending upon what is being measured.[120] This is partly because questionnaires developed for neurotypical subjects are not always valid for autistic people.[120] As of 2023, the Suicidal Behaviours Questionnaire–Autism Spectrum Conditions (SBQ-ASC) is the only test validated for autistic people.[120] According to some estimates, about a quarter of autistic youth[125] and a third of all autistic people[120][126] have experienced suicidal ideation at some point. Rates of suicidal ideation are the same for people formally diagnosed with autism and people who have typical intelligence and are believed to have autism but have not been diagnosed.[120] The suicide rate for verbal autistics is nine times that of the general population.[127]
Most people who attempt suicide are not autistic,[120] but autistic people are about three times as likely as non-autistic people to make a suicide attempt.[117][128] Less than 10% of autistic youth have attempted suicide,[125] but 15% to 25% of autistic adults have.[120][126] The suicide attempt rates are the same among people formally diagnosed with autism and those who have typical intelligence and are believed to have autism but have not been diagnosed.[120] The suicide risk is lower among cisgender autistic males and autistic people with intellectual disabilities.[120][128] The rate of suicide results in a global excess mortality among autistic people equal to approximately 2% of all suicide deaths each year.[128]
Burnout
Autistic people identify a subset of burnout that interacts uniquely with characteristics and experiences of autism. This burnout is termed autistic burnout. It is a prolonged state of exhaustion that results in reduced social and occupational skill capacity and quality of life.[129] Academic and clinical research has begun on the ways in which autistic burnout is experienced.[130]
Autistic people have said that autistic burnout can occur repeatedly, have cognitive and physical effects, be misunderstood by medical professionals, and adversely affect life goals in extended cases. But autistic people have also said that autistic burnout can often be a catalyst for diagnosis or other improved self-care and well-being. In particular, autistic people have anecdotally identified patterns of factors that lead to burnout.[131] Autistic people can also derive support from community members by sharing mitigating and coping strategies.[132] This is a reason that community psychology is used to study autistic communities.[133]
Other features
Autistic people may exhibit traits or characteristics that are not part of the formal diagnostic criteria but can nonetheless affect their personal well-being or family dynamics.[134]
- Some autistic people show unusual or notable abilities, ranging from splinter skills (such as the memorization of trivia) to rare talents in mathematics, music, or artistic reproduction, which in exceptional cases are considered a part of the savant syndrome.[135][136][137] One study describes how some autistic people show superior skills in perception and attention relative to the general population.[138] Sensory differences are found in over 90% of autistic people, and are considered core features by some.[139]
- More generally, autistic people tend to show a "spiky skills profile", with strong abilities in some areas contrasting with much weaker abilities in others.[140]
- Differences between the previously recognized disorders under the autism spectrum are greater for under-responsivity (for example, walking into things) than for over-responsivity (for example, distress from loud noises) or for sensation seeking (for example, rhythmic movements).[141] An estimated 60–80% of autistic people have motor signs that include poor muscle tone, poor motor planning, and toe walking;[139][142] difficulties in motor coordination are pervasive across the autism spectrum.[143][144]
- Pathological demand avoidance can occur. People with this set of autistic characteristics are more likely to refuse to do what is asked or expected of them, even to activities they enjoy.[citation needed]
- Unusual or atypical eating behavior occurs in about three-quarters of children on the autism spectrum, to the extent that it was formerly a diagnostic indicator.[134] Selectivity is the most common characteristic, although eating rituals and food refusal also occur.[145]
Digital media use
In his 2015 book NeuroTribes, Steve Silberman highlights the emergence of online communities centered around autistic people, such as Autism Network International—founded by Jim Sinclair—and Wrong Planet.[146] Silberman writes that these digital spaces offer a "natural home" for autistic people to communicate through written language.[146] A 2022 systematic review of 21 studies found that most studies reported moderate correlations between autism, problematic internet use, and gaming disorder.[147]
Causes
Summarize
Perspective
The exact causes of autism are unknown,[148][149][150][151] with genetics likely being the largest contributing factor. It was long presumed a single cause at genetic, cognitive, and neural levels underpinned the social and non-social features (the classic triad).[152] Increasingly, autism is assumed to be a complex condition with distinct, often co-occurring, causes for its core aspects.[152][153] It is unlikely that autism has a single cause;[153] research has identified many factors as potential contributors, including genetics, prenatal and perinatal (shortly after birth) factors, neuroanatomical anomalies, and environmental factors. It is possible to identify general factors, but much more difficult to pinpoint specific ones.[154]
Biological subgroups
Research into causes has been hampered by the inability to identify biologically meaningful subgroups within the autistic population[155] and by the traditional boundaries between the disciplines of psychiatry, psychology, neurology and pediatrics.[156] Newer technologies such as fMRI and diffusion tensor imaging help identify biologically relevant phenotypes (observable traits on brain scans) for neurogenetic studies of autism.[157] One example is lower activity in the fusiform face area of the brain, which is associated with a less pronounced perception of people versus objects.[158] It has been proposed to classify autism using genetics as well as behavior.[159]
Syndromic autism and non-syndromic autism
Autism can be classified into two categories, syndromic and non-syndromic. Syndromic autism refers to cases where autism is one of the characteristics associated with a broader medical condition or syndrome, representing about 25% of autism cases. The causes of syndromic autism are often known, and monogenic conditions account for approximately 5% of these cases. One of these is fragile X syndrome, which is found in around 2% of autistic people.[112] Non-syndromic autism, also known as idiopathic autism, represents the majority of cases, and its cause is typically polygenic and unknown.
Genetics
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether autism is explained more by rare mutations with major effects, or by rare multi-gene interactions of common genetic variants.[161][162] While these genetic variants are associated with a higher likelihood of being autistic, they do not individually determine whether someone will be autistic.[163] Complexity arises due to interactions among multiple genes, the environment, and heritable epigenetic factors (which influence gene expression without changing DNA sequence).[164] Many genes have been associated with autism through sequencing the genomes of autistic people and their parents.[165] But most of the mutations that increase autism likelihood have not been identified. Typically, autism is not traceable to a single-gene (Mendelian) mutation or chromosome anomaly, and no associated genetic syndrome selectively causes autism.[161] Numerous genes have been found, with most loci individually explaining less than 1% of autism cases[166] and having only small effects.[161] As of 2018[update], it appeared that between 74% and 93% of autism likelihood is heritable.[112] If parents have one autistic child, the chance of having a second autistic child ranges from 7% to 20%.[112] If the autistic child is an identical twin, the other will be autistic 36% to 95% of the time. A fraternal twin is autistic up to 31% of the time.[167] The large number of autistic people with non-autistic family members may result from spontaneous structural variation, such as deletions, duplications or inversions in genetic material during meiosis.[168][169] Hence, a substantial fraction of autism cases may trace to genetic causes that are highly heritable but not inherited, resulting from mutations not present in the parental genome.[170]
Hypotheses from evolutionary psychiatry suggest that these genes persist because they are linked to human inventiveness, intelligence or systemising.[171][172]
Current research suggests genes associated with autism, potentially numbering up to 1,000, ultimately affect neural development and connectivity in a similar manner characteristic of the autistic brain. These genes regulate neuronal processes including protein synthesis, activity, adhesion, and synapse formation/remodeling, as well as the balance of excitatory and inhibitory neurotransmission. Specific findings include lower expression of genes related to the inhibitory neurotransmitter GABA and higher expression of genes controlling glial (astrocytes) and immune (microglia) cells, correlating with increased numbers of these cells. Genes influencing the mTOR signaling pathway (cell growth/survival) are also under investigation.[173]
Autism may be under-diagnosed in women and girls due to an assumption that it is primarily a male condition,[174] but through genetic phenomena such as imprinting and X linkage, conditions can occur more frequently and present more intensely in males. Theories have been put forward for a genetic reason why males are diagnosed more often, such as the imprinted brain hypothesis and the extreme male brain theory.[175][176][177]
The likelihood of being autistic is greater with older fathers than with older mothers; two potential explanations are the known increase in the number of mutations in older sperm and the hypothesis that men marry later if they carry a genetic predisposition and show some signs of autism.[178]
Early life
Certain prenatal and perinatal complications may increase the likelihood of autism.[179] These include maternal gestational diabetes, maternal and paternal age over 30,[180][181][182] bleeding during pregnancy after the first trimester, use of certain prescription medication (e.g. valproate) or rubella infection during pregnancy,[183] and meconium in the amniotic fluid. None of these is conclusively related to autism, but each has been identified more frequently in children with autism than in their siblings who do not have autism and other typically developing youth.[184] It is unclear whether any single factor during the prenatal phase influences the likelihood of autism,[185] but complications during pregnancy may be a factor.[185]
Maternal nutrition and inflammation during preconception and pregnancy influences fetal neurodevelopment. Intrauterine growth restriction is associated with autism in both term and preterm infants.[186] Maternal inflammatory and autoimmune diseases may affect fetal tissues, potentially contributing to a genetic predisposition or influencing the nervous system's development.[187] Systematic reviews and meta-analyses have found that maternal prenatal infections, prenatal antibiotic exposure, and post-term pregnancies are associated with increased likelihood of autism in children.[188][189][190]
Exposure to air pollution during child pregnancy, especially heavy metals and particulates, may increase the likelihood of autism.[191][192] Unproven or disproven environmental factors claimed to contribute to autism include certain foods, infectious diseases, solvents, plastic chemicals (PCBs, phthalates, phenols), brominated flame retardants, alcohol, smoking, illicit drugs, vaccines,[193] and prenatal stress. Some, such as bad parenting[194] and the MMR vaccine, have been completely disproven.[195][196][197][198] Some evidence suggests a link between exposure to pesticides and autism.[199]
Disproven vaccine hypothesis
Parents may first become aware of autistic characteristics in their child around the time of a routine vaccination. This has led to unsupported and disproven theories blaming vaccine "overload", the vaccine preservative thiomersal, or the MMR vaccine for causing autism.[200] In 1998, British physician and academic Andrew Wakefield led a fraudulent, litigation-funded study that suggested that the MMR vaccine may cause autism.[201][202][203][204][205] His co-authors have since recanted the claims made in the study.[206]
Two versions of the vaccine causation hypothesis were that autism results from brain damage caused by either the MMR vaccine itself, or by mercury used as a vaccine preservative.[207] No convincing scientific evidence supports these claims.[32] They are biologically implausible,[200] and further evidence continues to refute them, including the observation that the rate of autism continues to climb despite elimination of thimerosal from most routine vaccines given to children from birth to 6 years of age.[208][209][210][211][212]
A 2014 meta-analysis examined ten major studies on autism and vaccines involving 1.25 million children worldwide; it concluded that neither the vaccine preservative thimerosal (mercury), nor the MMR vaccine, which has never contained thimerosal,[213] lead to autism.[214] Despite this, misplaced parental concern has led to lower rates of childhood immunizations, outbreaks of previously controlled childhood diseases in some countries, and the preventable deaths of several children.[215][216]
Etiological hypotheses
There are several hypotheses as to how and why people are autistic that integrate known causes (genetic and environmental effects) and findings (neurobiological and somatic). Some are more comprehensive, such as the Pathogenetic Triad, which proposes and operationalizes three core features (an autistic personality, cognitive compensation, neurobiological influences) that interact to cause autism,[55] and the Intense World Theory, which explains autism through a hyperactive neurobiology that leads to an increased perception, attention, memory, and emotionality.[217] There are also simpler hypotheses that explain only individual parts of the neurobiology or phenotype of autism, such as mind-blindness (a decreased ability for theory of mind), the weak central coherence theory, or the empathising–systemising theory.
Evolutionary hypotheses
Research exploring the evolutionary benefits of autism and associated genes has suggested that autistic people may have played a "unique role in technological spheres and understanding of natural systems" in the course of human development.[218][219] It has been suggested that autism may have arisen as "a slight trade off for other traits that are seen as highly advantageous", providing "advantages in tool making and mechanical thinking", with speculation that the condition may "reveal itself to be the result of a balanced polymorphism, like sickle cell anemia, that is advantageous in a certain mixture of genes and disadvantageous in specific combinations".[220] In 2011, a paper in Evolutionary Psychology proposed that autistic traits, including increased spatial intelligence, concentration and memory, could have been naturally selected to enable self-sufficient foraging in a more (although not completely) solitary environment. This is called the "Solitary Forager Hypothesis".[221][222][223] A 2016 paper examines Asperger syndrome as "an alternative prosocial adaptive strategy" that may have developed as a result of the emergence of "collaborative morality" in the context of small-scale hunter-gathering, i.e., where "a positive social reputation for making a contribution to group wellbeing and survival" becomes more important than complex social understanding.[224]
Some research suggests that recent human evolution may be a driving force in the rise of autism in recent human populations. Studies in evolutionary medicine indicate that as cultural evolution outpaces biological evolution, disorders linked to bodily dysfunction increase in prevalence due to lack of contact with pathogens and negative environmental conditions that once widely affected ancestral populations. Because natural selection favors reproduction over health and longevity, the lack of this impetus to adapt to certain harmful circumstances creates a tendency for genes in descendant populations to over-express themselves, which may cause a wide array of maladies, ranging from mental conditions to autoimmune diseases.[225] Conversely, noting the failure to find specific alleles that reliably cause autism or rare mutations that account for more than 5% of the heritable variation in autism established by twin and adoption studies, research in evolutionary psychiatry has concluded that it is unlikely that there is selection pressure for autism when considering that, like schizophrenics, autistic people and their siblings tend to have fewer offspring on average than non-autistic people, and instead that autism is probably better explained as a by-product of adaptive traits caused by antagonistic pleiotropy and by genes that are retained due to a fitness landscape with an asymmetric distribution.[226][227][228]
Co-occurring phenomena
Summarize
Perspective
,_dystonia,_epilepsy_and_schizophrenia.svg)
Genes associated with epilepsy
Genes associated with schizophrenia
Genes associated with autism spectrum disorder
Genes associated with dystonia
Autism is correlated or co-occurring with several personality traits and disorders.[158] Comorbidity may increase with age and may complicate the course of youth on the autism spectrum and make intervention and therapy more difficult. Distinguishing between autism and other diagnoses can be challenging because the traits of autism often overlap with symptoms of other conditions, and the characteristics of autism make traditional diagnostic procedures difficult.[229][230]
Co-occurring conditions
- The most common medical condition occurring in autistic people is seizure disorder or epilepsy, which occurs in 11–39% of autistic people.[231] The risk varies with age, cognitive level, and type of language impairment.[232]
- Intellectual disabilities are some of the most common co-occurring conditions with autism. As diagnosis is increasingly being given to people with lower support needs, there is a tendency for the proportion with co-occurring intellectual disability to decrease over time. In a 2019 study, it was estimated that approximately 30–40% of people diagnosed with autism also have intellectual disability.[233] Recent research has suggested that autistic people with intellectual disability tend to have rarer, more harmful, genetic mutations than those found in people solely diagnosed with autism.[234] A number of genetic syndromes causing intellectual disability may also be co-occurring with autism, including fragile X, Down, Prader-Willi, Angelman, Williams syndrome,[235] branched-chain keto acid dehydrogenase kinase deficiency,[236] and SYNGAP1-related intellectual disability.[237][238]
- Attention deficit disorder, which is generally more prevalent than autism (ca. 8% vs. 1%), is not directly related, though it is sometimes co-occurring with autism.[239] Difficulties in autism are often linked to behaviors that do not fit expectations, such as difficulties following directions, being cooperative, and doing things on other people's terms.[240] Characteristics similar to those of ADHD can be part of an autism diagnosis.[241]
- Various anxiety disorders tend to co-occur with autism, with overall co-occurring rates of 7–84%.[242] They are common among children on the autism spectrum; there are no firm data, but studies have reported prevalences ranging from 11% to 84%. Many anxiety disorders have characteristics that are better explained by autism itself or are hard to distinguish from autism's features.[243]
- Rates of co-occurring depression in autistic people range from 4–58%.[244]
- The relationship between autism and schizophrenia remains a controversial subject under continued investigation, and recent meta-analyses have examined genetic, environmental, infectious, and immune factors that may be shared between the two conditions.[245][246][247] Oxidative stress, DNA alterations and DNA repair have been postulated to play a role in the aetiopathology of both autism and schizophrenia.[248]
- Sensory processing disorder can also co-occur with autism, with co-occurring rates of 42–88%.[249]
- Starting in adolescence, some people with Asperger syndrome (26% in one sample)[250] fall under the criteria for the similar condition schizoid personality disorder, which is characterized by a lack of interest in social relationships, a tendency towards a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy.[250][251][252] Asperger syndrome was traditionally called "schizoid disorder of childhood".
- Genetic conditions – about 10–15% of autism cases have an identifiable Mendelian (single-gene) condition, chromosome anomalies, or other genetic syndromes.[253] An example is tuberous sclerosis, which is present in 1–4% of autistic people.[254]
- Several metabolic defects, such as phenylketonuria, are associated with autistic features.[255]
- Gastrointestinal problems are one of the most commonly co-occurring medical conditions in autistic people.[256] These are linked to greater social difficulties, irritability, language difficulties, mood changes, and behavior and sleep problems.[256][257][258] A 2015 review suggested that immune responses, gastrointestinal inflammation, autonomic nervous system differences, gut microbiome shifts, and food metabolites may be associated with neuroinflammation and differences in brain function.[257] A 2016 review concludes that enteric nervous system anomalies might play a role in neurological conditions such as autism. Neural connections and the immune system may be pathways through which signals or conditions originating in the gut can influence the brain.[258]
- Sleep problems affect about two-thirds of autistic people at some point in childhood. These most commonly include symptoms of insomnia, such as difficulty falling asleep, frequent nocturnal awakenings, and early morning awakenings. Sleep problems are associated with difficult behaviors and family stress, and are often a focus of clinical attention over and above the primary autism diagnosis.[259]
- Dysautonomia is common in autism, affecting heart rate and blood pressure and causing symptoms such as brain fog, blurry vision, and bowel dysfunction.[260]
- The frequency of autism is 10 times higher in mast cell activation syndrome patients than in the general population. This immunological condition causes cardiovascular, dermatological, gastrointestinal, neurological, and respiratory problems.[261]
- A 2024 Danish cohort study found increased risks for a multitude of co-occurring physical diseases, especially in infancy.[262]
- There is tentative evidence that gender dysphoria occurs more frequently in autistic people.[263][264]
Therapies and supports
Summarize
Perspective
There is no cure for autism[265] and this may not be an appropriate goal,[266][267] although therapies that target handling difficulties or co-occurring conditions remain important.[268] Those who have limited support needs are likely to have lessened autistic features over time.[269][270] Several therapies can help children with autism,[271] and no single one is best, with therapy typically tailored to the child's needs.[272] Studies of interventions have methodological problems that prevent definitive conclusions about efficacy,[273] but the development of evidence-based interventions has advanced.[274]
The main goals of therapy are to lessen associated difficulties and family distress, and to increase quality of life and functional independence. In general, higher IQs are correlated with higher responsiveness to interventions and larger intervention outcomes.[275][274] Behavioral, psychological, education, and skill-building interventions may be used to assist autistic people to learn life skills necessary for living independently,[276] as well as other social, communication, and language skills. Therapy also aims to reduce behaviors that do not fit expectations and build upon strengths.[277]
Intensive, sustained special education programs and behavior therapy early in life may help children acquire self-care, language, and job skills.[272] Although evidence-based interventions for autistic children vary in their methods, many adopt a psychoeducational approach to enhancing cognitive, communication, and social skills while minimizing behaviors that do not fit expectations. While medications have not been found to reduce core features, they may be used for associated characteristics, such as irritability, inattention, or repetitive behavior patterns.[278]
Non-pharmacological interventions
Intensive, sustained special education or remedial education programs and behavior therapy early in life may help children acquire self-care, social, and job skills. Available approaches include applied behavior analysis, developmental models, structured teaching, speech and language therapy, cognitive behavioral therapy,[279] social skills therapy, and occupational therapy.[272] Among these approaches, interventions either target autistic features comprehensively or focus on a specific area of difficulty.[274] Generally, when educating those with autism, specific tactics may be used to effectively relay information to these people. Using as much social interaction as possible is key in targeting the inhibition autistic people experience concerning person-to-person contact. Additionally, research has shown that employing semantic groupings, which involves assigning words to typical conceptual categories, can be beneficial in fostering learning.[280]
There has been increasing attention to the development of evidence-based interventions for autistic young children. Three theoretical frameworks outlined for early childhood intervention include applied behavior analysis (ABA), the developmental social-pragmatic model (DSP) and cognitive behavioral therapy (CBT).[279][274] Although ABA therapy has a strong evidence base, particularly in regard to early intensive home-based therapy, ABA's effectiveness may be limited by diagnostic severity and IQ of the autistic person.[281] A 2015 review deemed two early childhood interventions "well-established": individual comprehensive ABA and focused teacher-implemented ABA combined with DSP.[274]
Many people have criticized ABA, calling it unhelpful and unethical.[282][283][284] Sandoval-Norton et al. also discuss the "unintended but damaging consequences, such as prompt dependency, psychological abuse and compliance" that result in autistic people facing challenges as they transition into adulthood.[282] Some ABA advocates have responded to such critiques that, instead of stopping ABA, there should be movement to increase protections and ethical compliance when working with autistic children.[285]
Another evidence-based intervention that has demonstrated efficacy is a parent training model, which teaches parents how to implement various ABA and DSP techniques themselves.[274] Various DSP programs have been developed to explicitly deliver intervention systems through at-home parent implementation.
In October 2015, the American Academy of Pediatrics (AAP) proposed new evidence-based recommendations for early interventions in autism for children under 3.[286] These recommendations emphasize early involvement with both developmental and behavioral methods, support by and for parents and caregivers, and a focus on both the core and associated features of autism.[286] But a Cochrane review found no evidence that early intensive behavioral intervention (EIBI) is effective in reducing behaviors that do not fit expectations associated with autism in most autistic children, though it did improve IQ and language skills. The Cochrane review acknowledged that this may be due to the low quality of studies available on EIBI and therefore providers should recommend EIBI based on their clinical judgment and the family's preferences. No adverse effects of EIBI were found.[287] A meta-analysis in that same database indicates that due to the heterology in autism, children progress to differing early intervention modalities based on ABA.[288]
Autism intervention generally focuses on behavioral and educational approaches to target its two core features: social communication difficulties and restricted, repetitive behaviors. If characteristics continue after behavioral strategies have been implemented, some medications can be recommended to target specific characteristics such as restricted and repetitive behaviors (RRBs) or co-existing problems such as anxiety, depression, hyperactivity/inattention and sleep disturbance.[289] Melatonin, for example, can be used for sleep problems.[290]
Several parent-mediated behavioral therapies target social communication difficulties in children with autism, but their efficacy in reducing RRBs is uncertain.[291]
In children
Educational interventions often used include applied behavior analysis (ABA), developmental models, structured teaching, speech and language therapy and social skills therapy.[272] Among these approaches, interventions either target autistic features comprehensively or focus on a specific area of difficulty.[274]
The quality of research for early intensive behavioral intervention (EIBI)—a procedure incorporating over 30 hours per week of the structured type of ABA that is carried out with very young children—is low; more vigorous research designs with larger sample sizes are needed.[287] Two theoretical frameworks outlined for early childhood intervention include structured and naturalistic ABA interventions, and developmental social pragmatic models (DSP).[274] One interventional strategy utilizes a parent training model, which teaches parents how to implement various ABA and DSP techniques, allowing for parents to disseminate interventions themselves.[274] Various DSP programs have been developed to explicitly deliver intervention systems through at-home parent implementation. Despite the recent development of parent training models, these interventions have demonstrated effectiveness in numerous studies.[274] Early, intensive ABA therapy has demonstrated effectiveness in enhancing communication and adaptive functioning in preschool children;[272][293] it is also well-established for improving the intellectual performance of that age group.[272]
In 2018, a Cochrane meta-analysis database concluded that some recent research is beginning to suggest that because of the heterology of autism, there are two different ABA teaching approaches to acquiring spoken language: children with higher receptive language skills respond to 2.5 to 20 hours per week of the naturalistic approach, whereas children with lower receptive language skills require 25 hours per week of discrete trial training—the structured and intensive form of ABA.[288] A 2023 multi-site randomized control trial study of 164 participants showed similar findings.[35]
Similarly, a teacher-implemented intervention that utilizes a more naturalistic form of ABA combined with a developmental social pragmatic approach has been found to be beneficial for social-communication skills in young children, although there is less evidence for its reduction of global autistic characteristics.[274] Neuropsychological reports are often poorly communicated to educators, resulting in a gap between what a report recommends and what education is provided.[294] The appropriateness of including autistic children with varying levels of support needs in the general education population is a subject of current debate among educators and researchers.[295]
Pharmacological interventions
Medications may be used to target autistic features that interfere with integrating a child into home or school when behavioral intervention fails.[296] They may also be used for associated health problems, such as ADHD, anxiety, or if the person is hurting themself or aggressive with others,[296][297] but their routine prescription for autism's core features is not recommended.[298] More than half of US children diagnosed with autism are prescribed psychoactive drugs or anticonvulsants, with the most common drug classes being antidepressants, stimulants, and antipsychotics.[299][300] The atypical antipsychotic drugs risperidone and aripiprazole are FDA-approved for reducing associated aggressive and self-injurious behaviors.[278][301] But their side effects must be weighed against their potential benefits, and autistic people may respond atypically. Side effects may include weight gain, tiredness, drooling, and paradoxical aggression.[278] Some emerging data show that aripiprazole and risperidone may reduce restricted and repetitive behaviors (i.e., stimming; e.g., flapping, twisting, complex whole-body movements),[298] but due to the small sample size and different focus of these studies and the concerns about their side effects, antipsychotics are not recommended as primary ways to target RRBs.[302] SSRI antidepressants, such as fluoxetine and fluvoxamine, have been shown to be effective in reducing repetitive and ritualistic behaviors, while the stimulant medication methylphenidate can reduce co-occurring inattentiveness or hyperactivity in some children with these characteristics.[272] There is scant reliable research about the effectiveness or safety of pharmacological approaches for autistic adolescents and adults.[303] No known medication is approved for reducing autism's core features of social and communication difficulties,[278] although animal models indicate that postnatal administration of MDMA may be effective.[304] MDMA has also been investigated alongside psychotherapy to treat co-occurring social anxiety in autistic adults.[305]
Alternative medicine
A multitude of alternative therapies have been researched and implemented, and many have resulted in harm to autistic people.[272] A 2020 systematic review on adults with autism provided evidence that mindfulness-based interventions may decrease stress, anxiety, ruminating thoughts, anger, and aggression and improve mental health.[306]
Although popularly used as an alternative treatment for autistic people, as of 2018[update] there is no good evidence to recommend a gluten- and casein-free diet as a standard intervention.[307][308][309] A 2018 review concluded that it may be a therapeutic option for specific groups of children with autism, such as those with known food intolerances or allergies, or with food intolerance markers. The authors analyzed the prospective trials conducted to date that studied the efficacy of the gluten- and casein-free diet in children on the autism spectrum (4 in total). All of them compared gluten- and casein-free diet versus normal diet with a control group (2 double-blind randomized controlled trials, 1 double-blind crossover trial, 1 single-blind trial). In two of the studies, whose duration was 12 and 24 months, a significant reduction in autistic characteristics (efficacy rate 50%) was identified. In the other two studies, whose duration was 3 months, no significant effect was observed.[307] The authors concluded that a longer duration of the diet may be necessary to achieve the reduction of the autistic features.[307] Other problems documented in the trials carried out include transgressions of the diet, small sample size, the heterogeneity of the participants and the possibility of a placebo effect.[309][310][311] In the subset of people who have gluten sensitivity there is limited evidence that suggests that a gluten-free diet may reduce some autistic behaviors.[312][313][314]
The preference that autistic children have for unconventional foods can lead to reduction in bone cortical thickness with this risk being greater in those on casein-free diets, as a consequence of the low intake of calcium and vitamin D, but suboptimal bone development in autism has also been associated with lack of exercise and gastrointestinal disorders.[315] In 2005, botched chelation therapy killed a five-year-old child with autism.[316][317] Chelation is not recommended for autistic people since the associated risks outweigh any potential benefits.[318] Another alternative medicine practice with no evidence is CEASE therapy, a pseudoscientific mixture of homeopathy, supplements, and "vaccine detoxing".[319]
Results of a systematic review on interventions to address health outcomes among autistic adults found emerging evidence to support mindfulness-based interventions for improving mental health. This includes decreasing stress, anxiety, ruminating thoughts, anger, and aggression.[306] An updated Cochrane review (2022) found evidence that music therapy likely supports the development of skills in social interaction, verbal communication, and nonverbal communication.[320] There has been early research on hyperbaric oxygen therapy in children with autism.[321] Studies on pet therapy have shown positive effects.[322]
Prognosis
Summarize
Perspective
There is no evidence of an intervention that removes autism.[272][158] The degree of characteristics can decrease, occasionally to the extent that people lose their diagnosis of autism;[323][324] this occurs sometimes after intensive interventions[325] and sometimes not. It is not known how often this outcome happens,[281] with reported rates in unselected samples ranging from 3% to 25%.[323][324] Although core difficulties tend to persist, characteristics often become less pronounced with age.[164] Acquiring language before age six, having an IQ above 50, and having a marketable skill all predict better outcomes; independent living is unlikely in autistic people with higher support needs.[326]
Among others, academic Temple Grandin has advised against striving to cure autism, saying that if a cure were found, she would choose to stay the way she is. She wrote, "The skills that [autistic people] bring to the table should be nurtured for their benefit and [for the benefit of] society", adding, "If you totally get rid of autism, you'd have nobody to fix your computer in the future".[327][328]
The prognosis of autism describes the developmental course, gradual autism development, regressive autism development, differential outcomes, academic performance and employment.
Demographics
Summarize
Perspective
The World Health Organization estimates about 1 in 100 children were autistic between 2012 and 2021 with a trend of increasing prevalence over time. But this estimate may reflect an underestimate of prevalence in low- and middle-income countries.[5][6] The number of people diagnosed has increased considerably since the 1990s, and research suggests this may be due to increased recognition of autism.[31]
Males are about three times more likely to be diagnosed with autism than females.[329] Several theories about the higher prevalence in males have been investigated.[330] Girls, for example, are more likely to have associated cognitive disability, suggesting that less obvious forms of autism are likely being missed in girls and women.[331] Prevalence differences may also be a result of gender differences in expression of characteristics, with autistic women and girls showing less atypical behaviors and therefore being less likely to be diagnosed with autism.[332] Most professionals believe that race, ethnicity, and socioeconomic background do not affect the occurrence of autism.[333]
The Centers for Disease Control's Autism and Developmental Disabilities Monitoring (ADDM) Network reported that approximately 1 in 31 children in the United States is diagnosed with autism, based on data collected in 2022.[334] For 2016 data, the estimate was 1 in 54, compared to 1 in 68 in 2010 and 1 in 150 in 2000.[334] Diagnostic criteria for autism have changed significantly since the 1980s; for example, U.S. special-education autism classification was introduced in 1994.[193]
In the UK, from 1998 to 2018, autism diagnoses increased by 787%.[31] This is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness,[335][336][337] particularly among women,[31] though unidentified environmental factors cannot be ruled out.[338] It has been established that vaccination is not a factor for autism likelihood and is does not increase autism prevalence rates, if any change in the actual rate of autism (not just diagnosis) exists at all.[214][6]
Etymology
In 1912, Swiss psychiatrist Paul Bleuler coined the German term Autismus, which was rendered in English as autism. It is a portmanteau of the Greek word autos ("self") and suffix -ismos, denoting an action or state, that conveys the notion of "morbid self-absorption".[339]
Society and culture
Summarize
Perspective
An autistic culture has emerged, accompanied by the autistic rights and neurodiversity movements, that argues autism should be accepted as a difference to be accommodated instead of cured,[341][342][343][344][345] although a minority of autistic people might still accept a cure.[346] Worldwide, events related to autism include World Autism Awareness Day, Autism Sunday, Autistic Pride Day, Autreat, and others.[347][348][349][350]
Social-science scholars study those with autism in hopes to learn more about "autism as a culture, transcultural comparisons ... and research on social movements."[345] Many autistic people have been successful in their fields.[351]
Focused interests are commonly found in autistic people, sometimes leading to hobbies, vast collections, and activism. Environmental activist Greta Thunberg has spoken favorably about her autism diagnosis, saying that autism can be a source of life purpose, as well as forming the basis of careers, hobbies, and friendships.[352][353][340]
Neurodiversity movement
Some autistic people, as well as a growing number of researchers,[354] have advocated a shift in attitudes toward the view that autism is a difference, rather than a disease that ought to be treated or cured.[355][356] Critics have bemoaned the entrenchment of some of these groups' opinions, and that they speak to a select group of autistic people with limited difficulties.[343][357][345][358][359][360]
The neurodiversity movement and the autism rights movement are social movements within the context of disability rights, emphasizing the concept of neurodiversity, which describes the autism spectrum as a result of natural variations in the human brain rather than a disorder to be cured.[343][127] The autism rights movement advocates including greater acceptance of autistic behaviors, therapies that focus on coping skills rather than imitating the behaviors of those without autism,[361] and the recognition of the autistic community as a minority group.[361][360]
Autism rights or neurodiversity advocates believe that the autism spectrum is genetic and should be accepted as a natural variation in the human genome.[343] These movements are not without detractors; a common argument against neurodiversity activists is that most of them have relatively low support needs, or are self-diagnosed, and do not represent the views of autistic people with higher support needs.[360][362][363] Jacquiline den Houting explores this critique, determining that the voices of low-support needs autistics are "some of the most influential within the neurodiversity movement, although admittedly these voices are a minority within the advocacy community"; she suggests this is in part a shortcoming of the wider neurotypical community, referencing nonspeaking self-advocate Amy Sequenzia's writing.[364][365][undue weight? – discuss] Pier Jaarsma and Stellan Welin make the argument that only autistic people with lower support needs should be included under the neurodiversity banner, as autism with high support needs may rightfully be viewed as a disability.[360] The concept of neurodiversity is contentious in autism advocacy and research groups and has led to infighting.[359][345]
Events
Since 2011, the Autistic Self Advocacy Network has celebrated April as Autism Acceptance Month. In 2021, the Autism Society of America urged organizations to retitle Autism Awareness Day as Autism Acceptance Day, to focus on "more fully integrating those 1 in 54 Americans living with autism into our social fabric".[366]
Symbols and flags
Puzzle piece
In 1963, the British National Autistic Society chose a puzzle piece as its logo, due to its view of autistic people as suffering from a "puzzling" condition.[367][368] The logo, designed by board member Gerald Gasson, consisted of a green and black puzzle piece with four knobs, with a crying child at its center.[368] Other organizations and advocates adopted the puzzle piece as a symbol of autism, including American organization Autism Speaks, which uses a puzzle piece with one knob, two holes, one edge.
In 1999, the Autism Society of America designed the puzzle ribbon (an awareness ribbon patterned with red, yellow, cyan, and blue puzzle pieces) as a symbol of autism awareness.[368]
The puzzle symbol is controversial among autism advocates and rejected by many. It has been criticized as outdated, now that autism is better understood, as well as implying that autistic people are mysterious or incomplete, and for its association with Autism Speaks.[366] The autism rights movement and neurodiversity advocates have criticized Autism Speaks for its view of autism as a disease to be cured.[369][370][345][371]
National Autistic Society logo, circa 2000
Autism awareness ribbon, used by Autism Speaks from 2005
Current logo of Autism Speaks
Rainbow infinity
In 2004, neurodiversity advocates Amy and Gwen Nelson designed the "rainbow infinity symbol", originally as the logo for their advocacy group Aspies For Freedom. Many adopted the infinity symbol as a symbol for the autism spectrum.[367] The prismatic colors are often associated with the neurodiversity movement in general.[372]
In 2018, Julian Morgan wrote the article "Light It Up Gold", a response to the "Light It Up Blue" awareness campaign Autism Speaks launched in 2007.[373][374] Morgan pushed to use gold to symbolize autism, due its chemical symbol Au, from the Latin Aurum.[372]
Autism infinity symbol from 2013, featuring a rainbow gradient from left to right
Gold infinity loop, following Julian Morgan's 2018 push to use gold for autism
Flags
An autistic pride flag was created in 2005 by Aspies For Freedom for the first Autistic Pride Day, featuring a rainbow infinity symbol on a white background.[375]
As the rainbow infinity on a white background has become increasingly viewed as representative of neurodiversity in general,[372] several designs have been proposed for an autistic-specific flag.[376] In 2023, the People's History Museum featured a 2015 autistic pride design by Joseph Redford, featuring a rainbow infinity symbol, a green background for being true to one's nature, and a purple background for neurodiversity.[377]
An autistic/neurodiversity pride flag featuring a rainbow infinity, based on a design from 2013
The 2015 autistic pride flag by Joseph Redford
.svg)
Caregivers
Families who care for an autistic child face added stress for varying reasons.[378][379] Parents may struggle to understand the diagnosis and to find appropriate care options. They can take a negative view of the diagnosis, and may struggle emotionally.[380] More than half of parents over age 50 are still living with their child, as about 85% of autistic people have difficulties living independently.[381] Some studies also find decreased earnings among parents who care for autistic children.[382][383] Siblings of autistic children report greater admiration and less conflict with the autistic sibling than siblings of non-autistic children, like siblings of children with Down syndrome. But they reported lower levels of closeness and intimacy than siblings of children with Down syndrome; siblings of autistic people have a greater risk of negative well-being and poorer sibling relationships as adults.[384]
See also
Notes
- Medical diagnosis term. See Classification.
References
Further reading
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.